Punch and die apparatus with stripper mechanism



Aug. 16, 1955 Filed June 15, 1950 F. J. EGAN PUNCH AND DIE APPARATUS WITH STRIPPER MECHANISM 3 Sheets-Sheet 1 i 24 m. 25 m 27 A 26 Zmvcntor I n f n-cw}, W

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PUNCH AND DIE APPARATUS WITH STRIPPER MECHANISM Filed June 15, 1950 3 Sheets-Sheet 3 Suvenfor g (Ittornegs United States Patent 0 PUNCH AND DIE APPARATUS WITH STRIPPER MECHANISM Francis J. Egan, Cheshire, Conn., assignor to The Cold Forming Manufacturing Company, Cheshire, Conn., a corporation of Connecticut Application June 15, 1950, Serial N 168,336

4 Claims. (Cl. 10-11) This invention relates to a method of and apparatus for heading blanks and particularly a method and machine of this character which may be employed for upsetting or heading of hollow blanks, such as rivets, for example.

In the manufacture of articles of this kind a plurality of work operations is usually necessary upon the blank and, if a plurality of dies are employed, it is advantageous to transfer the workpiece from one die to the next so that the operations may be performed progressively in the same machine. In the making of a headed rivet, for example, the completed article is often relatively small, particularly with respect to its longitudinal dimension, and it is difiicult to transfer such a blank from one station to another after the head has been formed, due to the fact that it is difficult to engage the transfer fingers or tongs with the blank when the head is relatively large in relation to the length of the shank. On the other hand, it has been the practice to form the opening in the rivet after the formation of the head thereon. Therefore, it has been the custom to punch the opening in the rivet after the formation of the latter so that this punching operation is usually the last one to be performed. This is a limitation upon the depth of the opening which may be punched in the rivet as there is, of course, a limitation as to the depth of the 1 opening which may be made at one operation and after the head has been formed it is difficult to transfer the blank from one station to another or from one die to another for successive operations.

In the presently illustrated embodiment of my invention, I propose to form the opening in the blank prior to the heading operation so that the length of the blank will be slightly increased when the first operation is completed and it may, therefore, be readily engaged by the fingers of the transfer mechanism so as to be carried to the next station. As illustrated, I have shown a two-station machine wherein the opening is partially formed at the first station and then is deepened and the blank upset and headed at the second station. It will, however, be understood that if it is desirable, more or less than two stations may be employed and that an opening of any desired depth may be formed in the blank. That is to say, successive punching operations may be carried out in as many different stations as desired and the opening deepened at each station, the blank being transferred from one station to the next until it arrives at the last station where the upsetting and heading is effected. Thus, when the formation of the opening is effected prior to the upsetting or heading of the blank, the blank may be maintained at least at its original length and thus readily transferred from one station to another, and as many punching operations as necessary may be performed to effect an opening of the desired depth.

In addition, I provide improved die mechanism for forming the opening in the blank. With my improved mechanism the work is moved into the die opening so Li D that it is embraced by the die and thereafter the die and work are moved rearwardly while the piercing punch is held against movement, so that the opening is formed in the work While the latter is embraced by the die. In order to remove the work from the die after the operations have been completed, I provide a knock-out sleeve movable with respect to the die and also with respect to the punch so that the work may be stripped from the latter and also expelled from the opening in the die.

One object of my invention is to provide a new and improved method for forming a headed rivet or the like with an axial opening of uniform diameter in the end opposite the head.

Another object of the invention is to provide a novel and improved mechanism for making a rivet or like headed article provided with an opening in the end opposite that upon which the head is formed.

A still further object of the invention is the provision of novel mechanism for forming an opening in one end of a blank while maintaining the diameter of the blank at its original size so that the blank will not be shortened and may, therefore, be readily grasped by transfer fingers to be moved from one station to another.

A still further object of the invention is to provide novel die mechanism for forming an opening in a Work blank, the die mechanism comprising a die movably mounted in the die holder and comprising a sleeve slidably mounted in the die body and a punch for forming an opening in the blank, which punch is embraced by the sleeve.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a front elevational view of the die holder of a heading or upsetting machine embodying my invention, and the associated mechanism;

Fig. 2 is a sectional view on line 2--2 of Fig. 1;

Fig. 3 is a sectional view through the die mechanism showing the position of the dies and punches at the begining of the work operations;

Fig. 4 is a view similar to Fig. 3 showing the tools in positions occupied at another stage in the operation of the machine;

Fig. 5 is a view similar to Fig. 4 showing the final position of the tools;

Fig. 6 is a sectional view through the tools at one of the stations of the machine showing the final heading operation;

Fig. 7 is a sectional view through the die block at the first station of the machine on line 7-7 of Fig. 1;

Fig. 8 is an exploded view of the die mechanism employed in the first station of the machine;

Fig. 9 is an exploded view of the die mechanism em ployed in the second station of the machine; and

Fig. 10 is a perspective view of the knock-out sleeve and associated parts employed in the die mechanism shown in Fig. 8.

To illustrate a preferred embodiment of my invention, I have shown in the drawings a die holder 10 having die openings 11 and 12 therein in which are mounted the dies designated generally by the numerals 13 and 14.

The die holder is also provided with a cut-off die 15 having an opening 16 through which a length of stock 17 may be fed so that its end projects from the die opening as shown at 18. A cut-off knife of the usual form is shown at 19, this cut-oif knife being reciprocable across the face of the die by the usual mechanism (not shown) so that it will shear off the projecting end 18 of the stock and carry this end as a workpiece to the die 13.

Transfer mechanism of any suitable form may be employed to carry the workpiece from the die 13, after the tion-24 designed to engage the workpiece 25 (Fig. 3) and upon forward movement of the punch drive the workpiece into the opening of the die 13. Similarly a punch 26 is designed to cooperate with the die 14 at the second station ofthe machine, this die being provided with a centrally disposed pin 27 which is movable with respect to the punch 26 and which is also designed to engage the work at the second station of the machine and move itinto the opening in the die 14. Itwill be understood that the punches 23 and 26 may be moved forwardly. toward, and withdrawn from,- the cooperating dies by the usualmeans (not shown).

' The "die 13 employed at the first station of the machine i's 'shown more particularly in Figs. 7, 8 and-9. This die comprises a die body 30 having a die opening 31 therein and also is provided with an external shoulder 32 to engage a shoulder-33 of the die holder so as to limit outward movement'of the die body. As shown more I especially in the sectional views, Figs. 3 to 6, the die body 30 is hollow and the walls thereof are provided with upwardly opening slots 34 to receive springs 35 designed to contact a shoulder 36 on the backing plate 36 so that these springs act to force the dies outwardly so that the shoulder 32 will normally lie against the shoulder 33 and the face of the die be substantially flush with the face of the die holders as shown in Figs. 3 and 7.

Within the die body 30 is slidably mounted a cupsha ped member 37, the walls of which are provided with open ended slots 38 to accommodate the springs 35, this member being provided with a solid bottom portion '39. The bottom portion 39 of the member 37 is provided with an opening 40having a tapered upper portion '41 and in this opening is slidably received a punch 42'having a beveled head 43 complemental to the tapered opening 41 so that the outward projection of the punch or pin 42 will be limited by the seating of the head 43 in: the tapered portion 41 of the opening 40. It will be noted that the forward end of the wall of the cup shaped member 37 seats against the bottom of. the hollow portion of the die 30 in which the cup-shaped member is mounted.

I slidably embracing'theupunch 42 is a knockout sleeve 45 (Figs. 8 and 10), which sleeve is formed integrally with a disk 46 slidably mounted within the cup-shaped member37 so that, as shown in Figs. 3 and 4, this sleeve may move with respect to thedie body and also with respect to the punch 42. The movement of thefisleeve is limited in its outward direction by engagement of the disk 46 with 'theybottom of the hollow portion of the die body 30 as shown in Fig. 3 and is limited in the other direction by engagement 'of the disk 46 with the portion 39 of the cup-shaped member 37.

. Aplurality of pins 47 are secured to the disk 46 and are slidably received in openings in the portion 39 of the cup-shaped member 37, these pins being secured at their rear ends to a second disk or stop member 48. As shown in Fig. 7 for example, the frame member 72 is provided with an opening 50 of sufiicient diameter to receive the member 48 so as to permit the latter to pass into this opening'and be engaged by the knock=out pin 51 which may be actuated by any suitable mechanism '(not shown). V

Slidably mounted on the pins 47 is a circular block 53 designed to engage the rear face of the head 43 of the punch 42 and as-shown in Fig. 4, this block 53 in the operation of thedevice is designed to engage against stantially flush with the forward face of the die body 30,

it having been moved to this position by the knock-out 3 pin 51 which is, however, now ready to be withdrawn so as to permit the member 48 to move within the opening 50. The die 30 will be held in its forward position as shown by the springs 35 while the punch 42 and the block 53 may be in their forward positions as shown.

When the punch 23 is moved toward the die, the workpiece 25 will be moved into the die opening 31, as shown in Fig. 4. This moves the sleeve 45 and the associated.

parts rearwardly as shown in this figure, the disk 48 being received in the opening 50. Also the engagement of the upper end of the work with the punch 42 will move the latter rearwardly, carrying with it the disk 53 until the latter lodges against the shoulder 54of the die holder, which limits the rearward movement of this block. It will be noted that the'workpiece is entirely enclosed within the opening 31 of the die 30 and is confined therein by the reduced end 24 of the punch 23. The parts are now in position to begin the operation of eife'cting the opening in the rear end of the work.

Upon continued movement of the punch 23, the parts are moved from the position shown in Fig. 4 to that shown in Fig. 5. It will be noted'that the punch 23 engages the die body 30 and movesthe latter inwardly against the action of the springs 35 until the inner end of the die body is engaged against the shoulder 36 as shown in Fig. 5. The sleeve 45 is also moved rearwardly at this time as permitted by the movement ofthe die body and the member 37. The punch 42, however, is held against movement by engagement of the block 53 with the shoulder 54 as shown in'Fig. 4, so-that the sleeve 45 and the workpiece 25 are moved rearwardly while the pin is held against movement, thus causing the latter to project from the sleeve 45 and to pierce an opening this sleeve drives the Work from the die opening 31.

into the transfer fingers 21 and 22, by which the work is transferred to thenext station.-

It will be seen from the above that the work is first moved into the die opening causing a rearward :movement of the knock-out sleeve and also of the punch pin 42 to the position shown in Fig. 4. Thereafter a further advance of the punch effects a rearward movement of the die and sleeve, as shown in Fig.5, while the-punch 42 is held against movement .by the block 53, thus forming the opening in the work, while the latter is completely confined in the die opening so that .its cross sectional size is only slightly increased. The work is then transferred to the next station of the machine in the form shown at 25 in Fig. 3.

The die mechanism at the second station of the machine is quite similar to that described abovefor use at the first station. This mechanism comprises a die body 56 similar in form to the member 30, which body is provided with a counterbored opening 57 to form a shoulder on the work. The die body is also provided with slots 58 for reception of springs 59 serving the same function as the springs 35. Also the die body'56 is hollow and within the interior of the body is disposed the cup-shaped member 60 similar in form to the member 37, but of considerably shorter length. A punch pin 61 is provided within this body, the pin having a tapered head 62 resting in a similarly shaped opening 63 in the bottom of the member 60.

Surrounding the punch 61 is the knock-out sleeve 65 secured to the disk 66 to which are secured a plurality of pins 67 slidably mounted in openings in the bottom of the member 60. At their rear ends, these pins are secured to a disk member 68 similar to the member 48 and having the same function. Likewise a block 69, similar to the block 53, is slidably mounted upon the pins 67, this block acting as a stop for the punch 61', as shown, for example, in Figs. 4 and 5.

As shown in Figs. 4 to 6, the face of the backing plate 36 forms a shoulder 71 against which the block 69 is adapted to abut and by which the rearward movement of this block is limited, while the die frame 72 is provided with an opening 73 sufiiciently large to receive the disk 68 which is engaged by the knock-out pin 74, so that this disk together with the sleeve 65 may be driven forwardly to knock the work from the die after the operation has been completed.

When the workpiece 25 is transferred to the second station, as shown in Fig. 3, by the transfer mechanism 20, it is engaged by the pin 27 of the punch 26 and moved into the counter-sunk opening 57 in the die member 56. Initially the parts of the die mechanism stand in the position shown in Fig. 3, the die body being held forwardly by the compression springs 59. Upon advance of the punch the pin 27 pushes the workpiece into the die opening, as shown in Fig. 4, driving rearwardly the sleeve 65, the pins 67, and the disk 68. It will be understood that the knock-out pin 74 is free to move rearwardly at this time. Also the block 69 has been moved rearwardly against the shoulder 71 by the punch 61 so that further rearward movement of the latter is prevented and it will serve to effect a deeper opening in the end of the workpiece upon continued advance of the punch.

As shown in Fig. 5, the punch 26 has been advanced to its foremost position. During the latter part of its movement, the punch 61 has been held against movement, while the die body together with the sleeve 65 has been moved rearwardly until the rear end of the die body contacts the shoulder 71, while the disk 66 upon the sleeve 65 contacts the bottom of the cup member 60, which, in turn, is held against movement by the engagement of the block 69 against the shoulders 71. During this rearward movement of the die body 56 and associated parts, the punch 61, being held against movement, is driven into the work to form a deeper opening therein, as shown in Fig. 5.

Also the punch 26 moves forwardly over the pin 27 so that the lower end of the work is received in the flared opening 76 in the punch 26 and a shoulder 77 is formed on the workpiece by means of the countersunk opening 57 in the die.

In order to form the head upon the rivet, the workpiece 25 shown in Fig. 5, may remain in the opening of the die body 56 and a third punch 78 brought forward to engage the workpiece. This punch is suitably formed at its forward end, as shown at 79, to upset the metal of the blank which projects from the die and form the head 80 upon the work, as shown in Fig. 6.

The depth of the opening in the completed blank is not increased by the heading operation shown in Fig. 6 of the drawing. It will be understood, however, that if it is desired to provide a deeper opening than can conveniently be provided at two stations in the machine, as many stations as necessary may be provided prior to the transfer of the blank to the die 56 where the shoulder 77 is formed. Thus, by providing additional stations to perform the operations of punching the opening in the workpiece, as deep an opening as is desired may be effected prior to enlarging the cross sectional size of the blank or prior to shortening its overall length to such an extent that it is difficult to effect a transfer from one station to another.

It will be noted that as shown in Fig. 5 the disk 46 has been moved rearwardly to some extent relatively to the die as compared to the position shown in Fig. 4. This is due to the fact the workpiece is elongated to some extent, due to the flow of metal from the opening effected by the punch 42. The diameter of the blank is not substantially increased in this operation as the metal displaced to form the opening flows rearwardly to effect this elongation.

It will be seen that I employ straight sided piercing punches 42 and 61 so as to form in the blank a straight walled opening of uniform diameter throughout its length causing the metal displaced from the central portion of the workpiece to flow rearwardly about the punches. As the opening is of uniform diameter it may be tapped or threaded, if desired, which is not possible with a tapered opening such as is usually formed in articles of this character.

While I have shown and described a preferred embodiment of my invention and a preferred method of carrying out my improved process, it will be understood that the invention is not to be limited to'the details shown, nor the process to the steps described, but both are capable of modification and variation within the spirit of the invention and within the scope of the appended claims.

What I claim is:

1. In a mechanism of the class described, a die holder, a die movably mounted in the holder and provided with a die opening, said die having a rearwardly facing hollow portion, a plurality of springs between said die holder and said die to urge said die in a forward direction, a cupshaped member supported in the hollow portion of the die and facing in a forward direction, said cup-shaped member being provided with a plurality of open-ended slots guiding said springs, a knock-out sleeve mounted in said cup-shaped member and extending into the die opening, a plurality of guide members secured to said knockout sleeve and slidably projecting in a rearward direction through the bottom of said cup-shaped member, a knockout pin, and means secured to said guide members for engagement by the knockout pin.

2. In a mechanism of the class described, a die holder, a die movably mounted in the holder and provided with a die opening, said die having a rearwardly facing hollow portion, a plurality of springs between said die and said die holder to urge said die in a forward direction, a cupshaped member supported in the hollow portion of the die and facing in a forward direction, said cup-shaped member having a plurality of open ended slots for guiding said springs, a knockout sleeve mounted in said cupshaped member and extending into the die opening, a plurality of guide members secured to said knockout sleeve and slidably projecting in a rearward direction through the bottom of said cup-shaped member, a knockout pin, means secured to said guide members for engagement by the knockout pin, and a piercing punch movably mounted within said knockout sleeve.

3. In a mechanism of the class described, a die holder, a die movably mounted in the die holder and provided with a die opening, said die having a rearwardly facing hollow portion, a plurality of springs between said die and said die holder to urge said die in a forward direction, a cup-shaped member supported in the hollow portion of said die and facing in a forward direction, said cupshaped member having a plurality of open-ended slots for guiding said springs, a piercing punch movably mounted in said die and extending through the bottom of said cupshaped member and into the die opening, a knockout sleeve movably mounted in said cup-shaped member and embracing said punch, an abutment member for said punch located rearwardly of the bottom of said cupshaped member and limiting the rearward movement of said punch, a plurality of guide pins secured to said 7 knockout sleeve and slidably projecting rearwardly through the bottom of said cup-shaped member and through said abutment member, a disk "member secured to said guide, pins rearwardly of said abutment member, and a knockout pin engageable with said disk member.

4. In a mechanism of the class described, a die'holder, a die movably'mounted'in said die holder and having a die opening, said die having a rearwardly 'facing hollow portion, a plurality of springs between said die and said die holder to urge said die in a forward direction, a cupshaped member supported in the hollow portion of the die and facing .forwardly, said cup-shaped member being provided with open-ended slots to guide said springs, a piercing punchslidably mounted and extending through 8. the-bottom of said cup-shaped member and into the die opening, the bottom of said cup-shaped member providing an abutment to limit the forward movement of said punch, and an abutment member rearwardly of said cupshaped member ,to limit rearward movement of said punch, 7

References Cited in the file of this patent UNITED STATES PATENTS Lovisek Oct. 28, 1941 2,436,342 Wilcox l Feb. 17, 1948 2,542,864 Friedman 'Feb. 20, 1951 2,621,344 Friedman Dec. 16, 1952 Friedman June 15, 1954 

